A vacuum transfer system refers to a system where a vacuum pump is operated by means of high-speed compressed air so as to exhaust air from an inner space of a suction cup or a suction pad, and an object is gripped and transferred to a predetermined place using negative pressure while exhausting the air. The present invention relates particularly to a vacuum pump constituting the vacuum transfer system.
Referring to FIGS. 1 and 2, a conventional vacuum pump 1 includes: a hollow housing 2 provided with an inlet port 3 at a first end and an exhaust port 4 at a second end, and provided with an intake port 5 therebetween; and a multiple-step ejector 6 mounted inside the housing 2 in series. The vacuum transfer system is configured such that the vacuum pump 1 is locked to equipment using a means, such as a bracket, supporting the housing 2, and the vacuum pump, along with a suction cup 7 communicating with the ejector 6 by being connected to the intake port 5 and a robot arm connected to the suction cup 7.
The compressed air is supplied to the inlet port 3, passes through the ejector 6 at a high speed, and then is discharged through the exhaust port 4 to the outside. Here, the air inside the suction cup 7 is induced inside the ejector 6, and is discharged along with the compressed air. In the exhaust process described above, vacuum and negative pressure are generated in the inner space of the suction cup 7, and the vacuum transfer system grips and transfers an object to a predetermined place by using the negative pressure.
The vacuum pump 1 shown in the drawings is disclosed by Korean Utility Model Registration No. 274370, but is not different from a vacuum pump disclosed by Korean Patent No. 1029967, No. 1039470, No. 1066212, and No. 1351768 in terms of basic configuration and operation. Meanwhile, the vacuum pump 1 is utilized for constituting the vacuum transfer system on site, but the vacuum pump has following problems.
Firstly, it is impossible to change a direction of each port. For example, in the state where the vacuum pump 1 is mounted and locked to the equipment, it is generally not required to change the direction of the inlet port 3 and the exhaust port 4. However, the direction of the intake port 5 is often required to be changed according to a place of an object and a transfer location. The conventional vacuum pump 1 may not effectively respond to the necessity of changing direction.
Secondly, it is impossible to change a full length of the housing 2. For example, as in the vacuum pump disclosed by Korean Patent No. 1351768, in the case where one cylindrical ejector is mounted inside the housing, it is required to adjust a full length of the housing 2 according to a cartridge to be applied. However, the conventional vacuum pump 1 may not structurally respond to the necessity of adjusting the length.
Thirdly, in order to manufacture the conventional vacuum pump 1, a complex mounting arrangement is required. The complexity is shown throughout installation of the ejector 6 and assembly of the housing 2, and thereby assembling/disassembling of the vacuum pump 1 are difficult and productivity is lowered.